Adjust luminance gamma for Mac.
It appears that on macOS 10.13 smoothed subpixel antialiased black glyphs
are blit with a gamma of 2.0, but white are blit with a gamma of ~1.4 with
a smooth trasition between these. In macOS 10.14 smoothed black glyphs are
blit with a gamma of 2.0, but white are blit with a gamma ~1.0 with a
smooth transition between. The reason for this is to tone down the high
dilation of the outlines after autohinting.
In order to render like the platform, emulate this behavior by adjusting
the luminance value used to pick the mask gamma.
Bug: chromium:933137
Change-Id: I02d73c29bee1a3506b43598d78f07a03c968349f
Reviewed-on: https://skia-review.googlesource.com/c/196501
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2 files changed